1. Field of the Invention
The present invention relates to a sensor, and in particular to a humidity sensor, its detection method, and fabrication thereof.
2. Description of the Related Art
Conventionally, humidity sensors detect humidity in an environment and are generally used in air conditioning systems, dehumidifiers, dryers, and the like. Such wide use requires the humidity sensors to provide dependable operation.
Consequently, the humidity sensors can be mass produced at low cost if utilizing semiconductor process together with a simple structure and process, and lower material consumption.
Accordingly, an object of the invention is to provide a humidity sensor with a simple structure, its method of detection, and fabrication method thereof.
Another object of the invention is to provide a method for detecting the humidity in the environment.
According to the above mentioned objects, the present invention provides a humidity sensor. In the humidity sensor of the present invention, two comb-type electrodes with a plurality of teeth are disposed on a semiconductor substrate. A SiO2 sensing film is disposed between the teeth of the two comb-type electrodes on the substrate. A predetermined voltage is applied between the two comb-type electrodes, leakage current between the two electrodes is detected, and the humidity in the environment is measured according thereto.
In the fabrication method of the present invention, a SiO2 layer is formed on a semiconductor substrate as a sensing film. Two comb-type trenches, each with a plurality of teeth, are formed on the SiO2 layer and a conductive material is filled into the two comb-type trenches to form two comb-type electrodes.
The present invention also provides a method for detecting humidity in a predetermined environment. In the detection method, a humidity sensor is provided in the predetermined environment for a predetermined time, wherein the humidity sensor has a substrate, two comb-type electrodes deposed on the substrate, each having a plurality of teeth, and a SiO2 sensing film between the teeth of the two comb-type electrodes on the substrate. A predetermined voltage difference is then applied between the two comb-type electrodes, and a leakage current between the two comb-type electrodes is determined. Finally, the humidity in the predetermined environment is determined according to the leakage current.
A detailed description is given in the following embodiments with reference to the accompanying drawings.